I've had my 07 TL since January and its has headlight condensation in the driver side. Two weeks ago i noticed the HID in the headlight that has condensation burnt out. Yesterday i bought new HID's, just finished installing them, and now the HID still won't light up. Could my wiring be ruined because of the condensation? Or could it be something more simple that I'm missing? Thanks

 

Ballast could be fried.

It lies on the bottom of the headlight, and water could have made it down there.

 

Did you test the driver side headlamp wiring to see if theres power and a good ground before replacing or installing new hid lamp? And did you test the new hid lamp to confirm that it works before installing?

Before you do anything else confirm the driver side headlamp works by supplying power and ground.

Then check for power and ground.

Check headlamp fuse(s) and all fuses just incase. Then check headlamp relay.

 

The ballast itself is sealed. I would guess a short that blew a fuse

 

I have had a ton of issues with the ballast and HID igniters with my TL '04. One side worked and the other didn't so I had to troubleshoot and swap everything from side-to-side and see what the issue really was. Also swapped parts out from both sides as well. Eventually, found out it was the igniter.
Then a few months later, the other igniter went out...so now both are replaced and working great.

Food for thought.

 

The ballast is not sealed where it connects to the headlight.

It's happened hundreds of times to people who have leaky headlights and water creeps it's way to the ballast.